local mail server on ADSL?

[SoftDux]

Hi all

Can you believe it's the end of November already?

I need to setup a local mail server for a LAN, which will transfer mail to users locally, as well as on the internet. The question(s) I have has more todo with the domain(s), than the MTA itself.

I'll be using Zimbra, for it's near-MS exchange features.
If my domain is mydomain.co.za, how do I setup the domain for the local LAN, and do I need to worry about DYNDS if I'm going to use fetchmail to download mail from the remote mail server?
Currently I have the LAN setup as mydomain.local, but then I realise that emails will be in the forum of pete@mydomain.local / mary@mydomain.local - so, how would pete (who's real email is actually pete@mydomain.co.za) send an email to mary (who's real email is actually mary@mydomain.co.za), as well as to susan@someotherdomain.co.za ?

Does this make sense?
And is it worth it to setup the local LAN on DynDNS (let's say office.mydomain.co.za), being the primary MX & then configure the ISP server to be secondary MX?

[falko]

You must create an MX record for mydomain.co.za that points to your router's public IP address, and your router must forward port 25 to your mailserver.

If you want to send from your local mailserver, you should relay the mails through another mailserver because most dynamic IP addresses are blacklisted nowadays.